SPL: random integer

Hi, We're developing an Web application with DDW, Webdatablade en Informix UDO 9.14 UC6. I'm writing a recursive SPL procedure in which I need a unique integer every time this procedure is invoked (also when it is called by itself). I tried two things: - To use a variable which was created using the 'current' function. But the this date (year to fraction) variable stays the same in the entire procedure call. - Create a temp table wit a serial8. Do inserts an request its number en delete it again. Problem: multi-user application, so the users are intefering with each other, while inserting en selecting. Is there another way to create a random integer. Toine Schijvenaars.

Sorry, I should have consulted the newsgroup archive first. On 1997/12/08 Jonathan Leffler wrote: Since that's the case, we need a proper random number generator. On the assumption that the C Standard committee knew roughly what they were doing when they specified a random number generator in the ISO 9899:1990 standard, here's an implementation of that generator in two functions, sp_setseed(0 and sp_random(). The range of returned values is 0..32767. Note the comment about MOD. That was in a 9.12.UC2 IUS system. Yours, Jonathan Leffler (johnl@informix.com) #include <witticism.h> -- @(#)$Id: random.spl,v 1.2 1997/12/08 19:31:44 johnl Exp $ -- -- Simple emulation of SRAND and RAND in SPL -- Using random number generator suggested by C standard (ISO 9899:1990) CREATE PROCEDURE sp_setseed(n INTEGER) DEFINE GLOBAL seed DECIMAL(10) DEFAULT 1; LET seed = n; END PROCEDURE; CREATE PROCEDURE sp_random() RETURNING INTEGER;DEFINE GLOBAL seed DECIMAL(10) DEFAULT 1; DEFINE d DECIMAL(20,0); LET d = (seed * 1103515245) + 12345; -- MOD function does not handle 20-digit values... Dammit!! LET seed = d - 4294967296 * TRUNC(d / 4294967296); RETURN MOD(TRUNC(seed / 65536), 32768); END PROCEDURE; ----- Original Message ----- From: Toine Schijvenaars <tsch00@pop3.nl.net> Newsgroups: comp.databases.informix Sent: Monday, August 30, 1999 1:57 PM Subject: SPL: random integer > Hi, > > We're developing an Web application with DDW, Webdatablade en Informix UDO > 9.14 UC6. > > I'm writing a recursive SPL procedure in which I need a unique integer every > time this procedure is invoked (also when it is called by itself). > I tried two things: > - To use a variable which was created using the 'current' function. But the > this date (year to fraction) variable stays the same in the entire procedure > call. > - Create a temp table wit a serial8. Do inserts an request its number en > delete it again. Problem: multi-user application, so the users are > intefering with each other, while inserting en selecting. > > Is there another way to create a random integer. > Toine Schijvenaars. > > > > > > > >

Toine Schijvenaars wrote: > We're developing an Web application with DDW, Webdatablade en > Informix UDO 9.14 UC6. > > I'm writing a recursive SPL procedure in which I need a unique > integer every time this procedure is invoked (also when it is > called by itself). Usually, you can do this with a defaulted argument, as in: CREATE PROCEDURE xyz(..., level INTEGER DEFAULT 0) ... The user is told not to supply a level; the procedure bumps the level number each time it calls itself. If that is not adequate for you, then there are alternatives: > I tried two things: > - To use a variable which was created using the 'current' function. > But the this date (year to fraction) variable stays the same in > the entire procedure call. There are, apparently, some DBINFO options to return the real time. > - Create a temp table wit a serial8. Do inserts an request its > number en delete it again. Problem: multi-user application, so > the users are intefering with each other, while inserting en > selecting. Not if it is a temp table; each user gets their own temp table. > Is there another way to create a random integer. Of course. I'm pretty sure there are random number generator stored procedures in the IIUG archives (http://www.iiug.org). If not, then contact me at the office and I can send you what I've got archived in my system and try to get that to the IIUG too. -- Jonathan Leffler (jleffler@informix.com, jleffler@earthlink.net) Guardian of DBD::Informix v0.60 -- see http://www.perl.com/CPAN #include <disclaimer.h>

Toine Schijvenaars (tsch00@pop3.nl.net) wrote: : We're developing an Web application with DDW, Webdatablade en Informix UDO : 9.14 UC6. Check out ftp://www.iiug/org/pub/Informix_Archive/pub/random_udr.tar.Z This is a collection of random number generators written in 'C'. They return uniform, binomial and normally distributed pseudo-random values. -- ===================================================================== Paul Brown ^..^ pbrown@postgres.Berkeley.EDU (oo) - Oink! #include <std_disclaimer.h> "Think global - act loco!" - Zippy the Pinhead =====================================================================

You could try using a 'Last number' table and give each invokation of your SPL a successively higher number. If you do use a random function, you will need to program for the possibility of duplicates. Rudy On Mon, 30 Aug 1999 13:57:03 +0200, "Toine Schijvenaars" <tsch00@pop3.nl.net> wrote: >Hi, > >We're developing an Web application with DDW, Webdatablade en Informix UDO >9.14 UC6. > >I'm writing a recursive SPL procedure in which I need a unique integer every >time this procedure is invoked (also when it is called by itself). >I tried two things: >- To use a variable which was created using the 'current' function. But the >this date (year to fraction) variable stays the same in the entire procedure >call. >- Create a temp table wit a serial8. Do inserts an request its number en >delete it again. Problem: multi-user application, so the users are >intefering with each other, while inserting en selecting. > >Is there another way to create a random integer. > Toine Schijvenaars. > > > > > > > >